Assessment of air pollution tolerance index and anticipated performance index of roadside plants used for greenbelt development in the Kathmandu Valley, Nepal

Abstract

The study emphasizes the significance of evaluating performance index of plants in urban vegetation. The performance of some common roadside plants like Ficus benjamina, Buddleja asiatica, Jacaranda mimosifolia, Cinnamomum camphora, and Callistemon viminalis were assessed for air pollution tolerance index (APTI) and anticipated performance index (API). The study was conducted in polluted site (Balkhu-Koteshwor road section) and control site (Godawari Botanical Garden) in the Kathmandu Valley, Nepal. The APTI values are 7.71–11.86 in the control site and 8.83–12.54 in the polluted site. Based on APTI, Ficus benjamina, Cinnamomum camphora and Jacaranda mimosifolia are intermediate tolerant, whereas Buddleja asiatica and Callistemon viminalis are sensitive to air pollution. The API values for Jacaranda mimosifolia and Cinnamomum camphora are better, indicating that they are good performers in terms of air pollution tolerance. In contrast, Buddleja asiatica is evaluated as poor performer among the selected plant species. Tolerant plant species hold the potential to serve as effective vegetative traffic barriers and contribute to urban green belts. Conversely, sensitive plants can be utilized as bio-indicators of air quality.